This is basically a follow up of a very similar broader question.
Say I have two users, foo and bar. Only foo is logged in. If I manually log bar in I could set up Google Drive to auto start under System Preferences > Users & Groups > Login Items. In fact, it's probably already set up there, and this is what I currently do to achieve what I want: have 2 google drive sessions running simultaneously on my machine.
But, without this, how could I launch it without switching users from foo? And would it be possible to launch it even without logging in bar? If not, how could I automate logging in foo and bar after reboot? I'm just looking for ways to automate this process (of having to login another user) and keep Drive working even after eventual random failures.
Now, the similar question does have a very intersting answer suggesting using
launchd's bsexec and a trampoline-like process on bar, which would be quite complicated to achieve even with a script. And it does say "Apple Engineers do not recommend its general use", whatever that means.
If it were dropbox, I could be using dropbox cli. But Drive doesn't have such an option...